1. Field of the Invention
The present invention concerns a system for non-invasive medical treatment of the type wherein a therapy apparatus (such as a shockwave head in the case of a lithotripsy treatment) is moved on an orbit around a patient table or around a patient on this patient table.
2. Description of the Prior Art
A body region of the patient to be treated in a system of the above type is arranged in the isocenter of the orbit. The focus of the therapy apparatus (in the case of a shockwave head thus the focus of the ultrasonic waves emanating therefrom) is located in the isocenter or in the body region to be treated. A circular arc, known as a C-arm, is generally used for guidance of the therapy apparatus. In the case of a C-arm that is permanently fixed at a base, this C-arm must exhibit an arc length that is at least as large as the desired movement path of the therapy apparatus. The arc length of the C-arm can be shortened if it is supported so that it can be moved orbitally on the base. A therapy apparatus movably guided on a C-arm has the advantage that it can be positioned on different sides of the body of a patient without the patient having to be repositioned on the patient table. A system of this type is normally designed such that the base and further system parts are arranged on one side of the patient table, so the other side of the patient table can remain essentially free in order to allow unhindered access to the patient (such as for anesthesia purposes). If a therapy apparatus should now be brought into position on this side of the patient table, the therapy apparatus itself is less disruptive than the C-arm because the therapy apparatus is positioned relatively close to the patient. If, for example, a shockwave head is positioned in the 0° position (i.e. in the upper table position given vertical alignment of its shockwave axis) for lithotripsy treatment, the C-arm extends into the space above the patient at least up to this angle position. A treating doctor is thereby severely limited in terms of his or her freedom of movement in the region of the doctor's head.